Khmer Rouge survivors will hold a religious ceremony on Saturday at the “killing fields” of Cheoung Ek, where thousands of people were executed and buried in mass graves after they were tortured in various prisons under the regime.

Chum Mey, who lived through incarceration at the notorious Tuol Sleng prison, said he plans to tell the souls of the dead to be prepared for their killers to go on trial.

The first UN-backed tribunal hearing for Nuon Chea, Khieu Samphan, Ieng Sary and Ieng Thirith is June 27, marking the beginning of the court’s second trial. The four will be tried for war crimes, crimes against humanity, genocide and other related crimes.

“We have to appeal to those who died to remind them, to have them recall they were killed without doing wrong,” he told VOA Khmer. “We have to remind their ghosts to help them prop up the court, to try [the suspects] immediately and to find justice for those who died, because the four leaders are important, and no others are more important than them.”

The ceremony will include prayers and will allow participants to lay wreaths at mass graves that have become a symbol of the regime’s brutality and a popular tourist site outside the capital.

Chum Mey, who will be joined by other prison survivors and regime victims, said he thought the opening of the trial will begin a healing process for the trauma of the Khmer Rouge.

“Our thought is to find the truth as a direction, because in the future we need to have healing and reconciliation, and without justice and trust, it is hard to heal together,” he said.